There is no doubt that the effects of artificial lighting on humans, other living creatures, vegetation and the planet Earth in general is considerable. But just how considerable is it, and in what ways? New Israeli research has found that there is a significant positive connection between the strength of artificial lighting emitted from various places on the planet at night, as measured with the help of satellites, and the frequency of breast cancer.
This week Science, Technology and Space Minister Ofir Akunis, as part of Israeli Space Week, will award the Ilan Ramon Research Grant to Haifa University doctoral candidate Nataliya Rybnikova.
Rybnikova, a researcher in the fields of mathematics and economics, immigrated to Israel from Ukraine about two years ago and her Hebrew is still a bit shaky but her ambitious research speaks for itself.
Its premise is the claim that artificial lighting at night contains information that could characterize and predict many phenomena when it is monitored by satellites.
According to the research, artificial urban lighting in various parts of the globe can provide a great deal of information about a wide variety of areas — from economic activity, production output and urban planning through insights into the local way of life to finding additional factors for one of the greatest disorders of recent years — obesity.
As part of the study, the researchers developed, for the first time, tools to examine the signature of artificial light emitted by buildings and ground uses in urban areas at night, in order to identify the land use and institutions operating in a given locale.
In many senses artificial lighting has made humanity more productive and efficient, enabling work around the clock independent of the natural cycles of daylight and darkness.
Three Japanese researchers were awarded the Nobel Prize in physics for 2014 for inventing blue LEDs, or light-emitting diodes. These light bulbs, which are bright and energy-saving, are expected to illuminate areas of the globe that still remain dark.
In the modern way of life there is also a dangerous connection between artificial light and health problems. Its best-known and most familiar effect is on melatonin, also known as the “darkness hormone.” Melatonin levels change over the course of the day — they are low during the daytime and rise in the evening.
One of the connections that have been proven is between artificial lighting and obesity — for example, in shift workers, whose reversed way of life manages to confuse the melatonin mechanism.
The connection that has been found until now between artificial lighting at night and obesity in studies of relatively small groups is now getting reinforcement on an international level from Rybnikova’s new study, which is slated for publication in The International Journal of Obesity.
In the study, which conducted under the supervision of Prof. Boris Portnov at the University of Haifa, data on artificial lighting collected by an American meteorological satellite were cross-checked with World Health Organization data on the frequency of obesity in more than 80 countries. The Israeli researchers found that increased exposure to artificial lighting at night is significantly correlated with obesity, with high-strength lighting in about 70 percent of the cases matching high rates of obesity.
“This represents the first time that anyone has shown an association between obesity and light pollution on such a large scale,” Portnov says. According to the researchers, obesity could be mediated by physiological or behavioral changes in people who live in urban areas that are extensively lit, and possibly the lighting is a significant factor contributing to the obesity worldwide.
Prolonged exposure to artificial lighting at night is also connected to various types of cancer.
An article published recently in International Chronobiology found a significant connection between areas of the world characterized by high levels of artificial lighting at night and the frequency of breast cancer in the population.
The findings reinforce, on a much larger scale, results from previous studies that found a connection between prolonged exposure to artificial lighting and breast cancer at the level of the individual organism.
Dr. Hagit Schwimmer, director of the area of medical sciences at the Science Ministry, specializes in the study of physiology and sleep. She explains that “there are a great many studies indicating a connection between obesity and changes that occur in the wake of exposure to artificial lighting.”
According to her, over time satellite photographs have also shown changes in the kinds of artificial light itself: Over the years white light (like that emitted by LED bulbs, for example) has become more dominant and this is the type that is more damaging to melatonin production and therefore the most harmful.”
Various studies conducted in Israel have also shown a connection between exposure to artificial lighting at night and the frequency of various types of cancer.
“Studies in specific neighborhoods in north and south Tel Aviv, with no connection to any kind of socioeconomic situation,” explains Schwimmer, “have shown that the more artificial lighting there is in a neighborhood, the higher the frequency of breast cancer and prostate cancer.”
Rybnikova says the 500,000-shekel ($126,000) grant will help to sustain her research over the next two years. She hopes to continue to analyze the light signatures coming from the satellite photographs and convert them into valuable local and international information.